Java recursion return problem[SOLVED]

Laika1986

Hey Guys I am trying to implement a recursive method that computes the factorial of a number. The code i have works fine however it returns nothing. I know the code works as i have printed the value but it prints through each calculation.any help would be great. The first code is my main class and the second contains the method thats is troubling me

public class RecursiveMain {
    /**
     * @param args
     */
    public static void main(String[] args) {


        Iterative it = new Iterative();
        Recursive rec = new Recursive();
        
        
       // it.subtraction(100);
       // rec.myDecrementer(100);
       // it.factorialI(5);
        rec.factorialR(5);

    }
}

public class Recursive {
	
	
	public void myDecrementer(int a){
		
		if(a>0){
			a--;
			System.out.println(a);
			myDecrementer(a);
		if(a==0){
			
				System.out.println("The program has finished");
			}
			
		}
	}
	
	public int factorialR(int n){
		int r;
		if(n==0)
			return 0;
		r=factorialR(n-1)*n;
		return r;
	
		
		
		
}
	
	
	
	
	
	

}

Procasinator

What do you mean returns nothing?
Is it possible that all you mean is it prints nothing?

Should you be printing the rec.factorialR(5)?

System.out.println(rec.factorialR(5));

Laika1986

Procasinator wrote: »

What do you mean returns nothing?
Is it possible that all you mean is it prints nothing?

Should you be printing the rec.factorialR(5)?

System.out.println(rec.factorialR(5));

Sorry you are correct it prints nothing!ill will try your method and report back!

I'm a bit of a noob regarding java so this returning blank has thrown me a little I think. What i have done is probably right it's when nothing prints to screen i assumed that it didnt compute properly

Niall09

What Procasinator said.

Also, remove

System.out.println(a);

from your decrementor method. That is why it is printing all the calculations.

Laika1986

Niall09 wrote: »

What Procasinator said.

Also, remove

System.out.println(a);

from your decrementor method. That is why it is printing all the calculations.

I need that for part one of the assignment. Should i just create a separate class for the method?

conor.hogan.2

Base case should return 1 not 0 in the Recursive class and the factorialR method.

Store the answer in a variable in main and print it out. Or System.out.println(rec.factorialR(5)); as others have said.

You have the decrementor method call commented out so it does not get printed in the example you posted so it is fine.

Laika1986

conor.hogan.2 wrote: »

Base case should return 1 not 0 in the Recursive class and the factorialR method.

Store the answer in a variable in main and print it out. Or System.out.println(rec.factorialR(5)); as others have said.

You have the decrementor method call commented out so it does not get printed in the example you posted so it is fine.

Works like a treat!!Thanks to everyone for their I really appreciate it!

conor.hogan.2

Laika1986 wrote: »

Works like a treat!!Thanks to everyone for their I really appreciate it!

I would recommend always using {} for your ifs and elses btw and change the "n==0" to "n <= 1" too.